Tool with chromium-containing functional layer

摘要

Cutting tool has a substrate and a multilayer coating deposited by PVD. The coating comprises a base layer of one or more identical or different layers of a nitride or carbonitride which contains at least aluminium (Al) and a chromium-containing, oxidic functional layer. Attachment of the chromium-containing functional layer is improved by an intermediate layer of one or more oxides or oxide nitrates of the metals Al, Cr, Si, and/or Zr provided between the base layer and the functional layer. The intermediate layer has a cubic structure and the chromium-containing functional layer is selected from chromium oxide (Cr2O3), chromium oxynitride, aluminium-chromium oxide (AlCr)2O3, aluminium-chromium oxynitride or a mixed oxide or mixed oxynitride of aluminium, chromium and further metals of (AlCrMe1, Men)2 oxide or (AlCrMe1, Men)2 oxynitride, where Me . . . Men means one or more further metals, selected from Hf, Y, Zr and Ru, and wherein the functional layer has a rhombohedral structure.

主权项

1. Cutting tool including a substrate of hard metal carbide, cermet, steel or high-speed steel (HSS) and a multi-layer coating deposited thereon by a PVD process, wherein starting from the substrate the multi-layer coating comprises the following sequence of layers:
a) a base layer consisting of one or more identical or different layers arranged one on top of another of a nitride or carbonitride and which contains at least aluminium (Al) and optionally one or more further metals selected from Ti, Cr, Si, Y, Ru and Mo, b) an intermediate layer arranged on top of the base layer and consisting of one or more oxides or oxynitrides of the metals Al, Cr, Si, and/or Zr, the intermediate layer exhibiting a cubic structure, and c) a chromium-containing functional layer arranged on top of the intermediate layer and selected from chromium oxide (Cr2O3), chromium oxynitride, aluminium-chromium oxide (AlCr)2O3, aluminium-chromium oxynitride or a mixed oxide or mixed oxynitride of aluminium, chromium and further metals (AlCrMe1, . . . Men)2 oxide or (AlCrMe1, . . . Men)2 oxynitride, in which Me1, . . . Men means one or more further metals selected from Hf, Y, Zr and Ru, the functional layer exhibiting a rhombohedral structure.